The total amount of money that Harry and Ron had was the same number that Neville had. The total amount of money that Neville and Ron had was 4 times the amount that Harry had.

a. What was the ratio of the amount of money that Harry had to the amount of money that Ron had to the amount of money that Neville had?
b. Ron had $54. How much money did the 3 children have altogether?

so, what have they told you?

n = h+r
n+r = 4h
(a) you want h:r:n
n = h+r = 4h-r
so 3h = 2r and now we have
h = 2/3 r
n = 5/3 r
h:r:n = 2/3 : 1 : 5/3 = 2:3:5
(b) 2:3:5 = 36:54:90
36+54+90 = 180